Agricultural combines are large machines that harvest, thresh, separate, and clean agriculturally planted crop carrying corn. The clean corn attained in this way is stored in a corn tank arranged on the combine. The threshed-out straw is usually either chopped and distributed on the field across the width of the cutter head or conducted around the straw chopper and deposited in a swath on the field without being chopped in order to be able to retrieve it later by means of a baler. The harvested crop remains that remain at the rear outlet of the cleaning arrangement such as chaff and small straw particles are distributed across the field by a chaff spreader or conducted through the straw chopper and distributed across the field. The latter solution has the advantage that no separate chaff spreader is needed, but requires that the straw be conducted past the straw chopper to the rear in the swath deposit mode. Examples of such combines are described in DE 100 64 356 A and DE 102 56 744 A.
In DE 100 64 356 A sheet metal guide vane is arranged underneath the rear straw outlet of an axial separating arrangement, that is connected in joints at its lower end pivoted about a pivot axis to the frame of the combine and can be pivoted between a swath deposit position in which it extends at an angle upward and to the front and conducts the straw ejected by the axial separating arrangement to the ground at its rear side to the rear of the straw chopper, and a chopper position in which it extends approximately vertically and conducts the straw at its forward side into the straw chopper arranged underneath the pivot axis. Chaff and small straw particles are conducted in both operating modes by the suction effect of the straw chopper from the cleaning into the straw chopper.
DE 102 56 744 A proposes that a straw guide element be arranged that is connected in joints, pivoted about a pivot axis extending horizontally and transverse to the forward operating direction, underneath the axis of rotation of an ejection drum arranged under the outlet of an axial separating arrangement. Accordingly, the straw can be conducted into the straw chopper or conducted past its rear side onto the ground, in that the straw guide element is pivoted into the corresponding position. Chaff and small particles are conveyed by means of a conveyor sheet into the inlet of the straw chopper.
In the case of the two arrangements described the deflections of the harvested crop performed by pivoted guide elements that are otherwise rigid and stationary is seen as detrimental for conducting the straw to the straw chopper or for the deposit in a swath to the rear of the straw chopper, in that the attainable throughput is limited by the friction of the harvested crop on the guide elements. A further problem is seen in the fact that in view of capacity increases of more modern combines which lead to increasingly long cleaning arrangements the straw chopper must be arranged further to the rear which further complicates the conveying of the straw from a separating arrangement to the straw chopper either without a driven conveying arrangement (DE 100 64 356 A) or with only one conveying arrangement (DE 102 56 744 A).
DE 36 44 900 A describes another combine in which an adjustable straw guide surface is provided that can be pivoted between a swath deposit position and a straw chopper position and is located between the rear outlet of a straw shaker and the inlet to the straw chopper. The straw guide surface is connected in joints at its lower end to the frame of the combine and can be pivoted about a horizontal pivot axis extending transverse to the direction of operation between the swath deposit position, in which it extends at an angle upward and to the rear and guides the straw ejected from the straw shaker to the ground ahead of the straw shaker, and a straw chopper position, in which it extends at an angle upward and to the front and guides the straw into the straw chopper arranged to the rear of the pivot axis. In one embodiment the straw guide element is configured as a conveyor belt. In this arrangement the disadvantage is seen in the fact that a separate chaff distributor is required in order to distribute the chaff and small straw particles given off by the cleaning arrangements across the field, since the straw is deposited on the ground ahead of the straw chopper in the swath deposit mode.
U.S. Pat. No. 7,066,810 B is seen as forming a class and describes a further combine in which a conveyor belt operating in overshot mode is arranged that follows to the rear of the outlet of the axial separating arrangement with an ejection drum arranged downstream. At the rear end of the conveyor belt sheet metal guide surfaces are attached that form a duct directed downward in the chopper mode, and conduct the straw into a straw chopper arranged underneath and to the rear of the rear end of the conveyor belt that chops it and distributed it across the field. The harvested crop remains from the cleaning arrangement are distributed across the field. Furthermore, the sheet metal guide surfaces can be brought into a swath deposit position in which they guide the straw onto the field to the rear of the straw chopper. Furthermore, a position of the harvesting crop remains distribution arrangement is provided, in which the sheet metal guide surface forming the forward wall of the duct is pivoted at an angle to the rear, so that the chopped crop is moved downward ahead of the straw chopper and is deposited there on the ground mixed with the chaff from the chaff spreader. In place of the sheet metal guide surface, the conveyor belt can also be pivoted into an approximately vertical position about the axis of rotation of its front or its rear deflecting roll, in which it guides its straw onto the ground that was thrown by the ejection drum against its forward side. Here it can be seen as detrimental that several chaff distributors are necessary and that a multitude of moveable parts are required, in order attain the various modes of operation.